After a lifetime of dreaming of traveling the world, 78-year-old homebody Carl flies away on an unbelievable adventure with Russell, an 8-year-old Wilderness Explorer, unexpectedly in tow. Together, the unlikely pair embarks on a thrilling odyssey full of jungle beasts and rough terrain.

By tying thousands of balloon to his home, 78-year-old Carl Fredricksen sets out to fulfill his lifelong dream to see the wilds of South America. Right after lifting off, however, he learns he isn't alone on his journey, since Russell, a wilderness explorer 70 years his junior, has inadvertently become a stowaway on the trip.